Pls. follow the steps as below:

1. download the update file.

2. copy the file update.zip to the TF card or Tablet memory ( I think it's better for TF card), and the file name must be " update.zip", pls kindly note that.

3. put the TF card into the tablet, then start the tablet, choose " Settings" -- "About tablet" -- "Local update" , then choose the file "update.zip" from TF card.

4. then upgrade the tablet.

5. finish it.